The novel was adapted for film with a screenplay by Fowles, directed by Guy Green, and released in 1968. It starred Michael Caine as Nicholas Urfe, Anthony Quinn as Maurice Conchis, Anna Karina as Alison, Candice Bergen as Lily/Julie, and Julian Glover as Anton. It was filmed in the island of Majorca. The adaptation was generally considered a failure as film.
Caine said that it was one of the worst films he had been involved in, along with The Swarm and Ashanti, because no one knew what it was all about. Woody Allen was quoted in 2005 saying, "If I had to live my life again, I'd do everything the same, except that I wouldn't see The Magus." Despite the critical failure, the film was nominated for a BAFTA Award for Best Cinematography. In recent years, it has gained a cult following, which resulted in its commercial release on DVD in the United States on 17 October 2006.